GSH, Asc and iron availability affects root architecture and gravitropic response in Arabidopsis.

RAMÍREZ, LEONOR; LAMATTINA, LORENZO

Mendoza

Congreso; SAIB; 2012

Root growing is affected by environmental factors. Among the most critical, nutrient availability can profoundly shape root architecture. The increase of the density and length of root hairs is a well studied response in plants growing under iron deficiency. However, the effect of nutrient deprivation on the primary root (PR) length, lateral roots (LR) length and density, and gravitropic response is poorly understood. It has been already established that reactive oxygen species (ROS) and auxin can modulate the PR length, LR density and length and the gravitropic response in plants. In this work, we analyzed the effect of iron availability and cell redox regulation on the root architecture in Arabidopsis plants. Glutathione (GSH) and ascorbate (Asc), two multifunctional metabolites that are important in redox balancing affect differentially the PR length and LR length and density. Under iron deficiency, Asc affects the root architecture stronger than GSH. In addition, GSH inhibits the gravitropic response in Arabidopsis under iron deprivation but not in iron sufficiency. A link between GSH, Asc, ROS, auxin and iron availability is discussed. Supported by CONICET, ANPCyT, UNMdP.